Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been...Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been prepared by traditional hydrothermal method directly using a zinc foil as both source and substrate. We found that we could tune the optical properties of ZnO samples by changing the temperature. In particular, increasing temperature could significantly reduce the reflectivity of solar energy in the visible range. We speculate that the phenomenon is relevant to the sharp cone morphology of the ZnO nanorods grown on the surface of Zn foils, which furthermore enhance refraction and reflection of light in the nanorods. The capacity to improve the light absorption of ZnO may have a bright application in raising the efficiency of solar cells.展开更多
An improved single image dehazing method based on dark channel prior and wavelet transform is proposed. This proposed method employs wavelet transform and guided filter instead of the soft matting procedure to estimat...An improved single image dehazing method based on dark channel prior and wavelet transform is proposed. This proposed method employs wavelet transform and guided filter instead of the soft matting procedure to estimate and refine the depth map of haze images. Moreover, a contrast enhancement method based on just noticeable difference(JND) and quadratic function is adopted to enhance the contrast for the dehazed image, since the scene radiance is usually not as bright as the atmospheric light,and the dehazed image looks dim. The experimental results show that the proposed approach can effectively enhance the haze image and is well suitable for implementing on the surveillance and obstacle detection systems.展开更多
基金supported by the National Natural Science Foundation of China(No.11575187)the National Key Research and Development Program(No.2016YFB0700205)
文摘Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been prepared by traditional hydrothermal method directly using a zinc foil as both source and substrate. We found that we could tune the optical properties of ZnO samples by changing the temperature. In particular, increasing temperature could significantly reduce the reflectivity of solar energy in the visible range. We speculate that the phenomenon is relevant to the sharp cone morphology of the ZnO nanorods grown on the surface of Zn foils, which furthermore enhance refraction and reflection of light in the nanorods. The capacity to improve the light absorption of ZnO may have a bright application in raising the efficiency of solar cells.
基金supported by the National Natural Science Foundation of China(61075013)the Joint Funds of the Civil Aviation(61139003)
文摘An improved single image dehazing method based on dark channel prior and wavelet transform is proposed. This proposed method employs wavelet transform and guided filter instead of the soft matting procedure to estimate and refine the depth map of haze images. Moreover, a contrast enhancement method based on just noticeable difference(JND) and quadratic function is adopted to enhance the contrast for the dehazed image, since the scene radiance is usually not as bright as the atmospheric light,and the dehazed image looks dim. The experimental results show that the proposed approach can effectively enhance the haze image and is well suitable for implementing on the surveillance and obstacle detection systems.
